The present invention relates to a structure of a car body which runs on a track.
A car body is comprised of side structures, a roof, an underframe constituting the floor, and ends constituting the end portions in the longitudinal direction. The side structures, the roof, and the underframe are constituted by bonding plural extruded materials together. The longitudinal directions of the extruded materials are positioned toward the longitudinal direction of the car body. A large proportion of the extruded materials are hollow-shaped materials. Especially, the underframe is made from hollow-shaped materials. This technique is disclosed in Japanese Patent Laid-Open No. 09-309164 (EP 0797043A2).
The process starts with producing the side structures, the roof, the underframe and the ends first, and then assembling the components to obtain a car body. The side structures are formed with one or more doorways and windows. Therefore, extruded materials provided with notches for the doorways and the windows are juxtaposed and bonded to obtain the side structure.
The doorways are formed on the side structure. The doorway is large both in height and width. Particularly, the width of the doorway in a commuter train is large.
Therefore, in a case where the produced side structure provided with the doorways is transferred to an assembling process, the side structure tends to deform at the region with the doorways. Also, when the side structure is produced using hollow-shaped materials, the upper surfaces are bonded first, and further bonding is performed by turning the side structure upside down. In such case, the side structure tends to deform at the region with the doorways.
Therefore, the car body must be produced with extra care, causing troublesomeness.
The object of the present invention is to provide a car body that could be produced with ease.
The above-mentioned objects could be achieved by manufacturing a side structure, wherein:
a second hollow-shaped material is bonded to lower ends of a plurality of first hollow-shaped materials;
the lower end portion of the second hollow-shaped material is formed so that a face plate at the external side of a car has a lower end portion which projects further downward than a lower end portion of a face plate at the internal side of the car;
the lower end portions of the two face plates are connected with a first rib;
the lower end portion of the face plate at the internal side of a car and the face plate at the external side of a car are connected with a second rib; and
members of the second hollow-shaped material positioned above the second rib are removed from said material at one or more doorways.